Why is my C drive full?

My C drive has 50.7 GB. After checking the C drive space, I found that I only have 1 GB free space for some reason.
After I click into my C drive and add up all the spaces that are taken up by the folders, I found out that I only used around 10 GB of space, which means I have about 40 GB of free space.
Now I am having not enough space in my C drive to download things. Can anyone tell me how I can free up more space and what is the problem with my C drive. I am pretty sure I did not download 49 GB of things. Thanks!

After using the WinDirStat, it shows that my total of C drive is 50.8 GB (from the window that pops up where I can choose the drives). However, after they analyse it, it shows that my C drive size is 7.2 GB.

What is the difference between total and size? (Sorry but I am not very good at computers) And is it possible to free up space?

dragont225, the Total from the selection window is the capacity of the drive. The Size from the analysis window is the amount that is used.

On the drive selection screen it gives Total, Free, and Used/Total as a percentage. What are these 3 numbers? It sounds like there should be plenty of free space.

To make more space, use the Disk Cleanup utility. Open My Computer, right-click on the C: drive and select Properties. Click on the Disk Cleanup button and let it work. You can check all of the boxes, except "Compress Old Files". I recommend against that one because it can slow down your system.

If your system uses 10GB (which would be very little), then you should have about 33GBs free pace. On a 50GB disk partition there could be about 7.5GBs used by the shadowstorage. That space you don't see. Further, if you installed SP1, there could be the SP1 uninstaller using a couple of Gigs, plus a lot of temporary files (although not as many to leave you only 1GB of free space). Do the cleanup that ScottW recommended, report the result, and then we'll see from there.

Something is really not right. Can you post a snip of the first WinDirStat analysis window that you get when you run WinDirStat - but only the top part with the numbers, not the multicolor picture below. And from where do you get this: "After analyzing the C drive, the size is 6.6 GB."?? And what is it supposed to mean??

A snip you do with the snipping tool which you find in All Programs > Accessories. Just make sure to file your snip - File > Save as. For posting, do this:
1. Create your account at http://photobucket.com/ - real easy
2. Use the folder with your name on it or create a subfolder (recommended). You do that on the left side where it says "New Album" > Save
3.Go to "Upload Images and Videos", somewhere in the middle. Now click on "Choose Files". This will most likely bring up your "Pictures" folder (but you can select another folder). Double click on the file you want to upload. After a few seconds you will see it. Now single click on your picture. On top of the picture you will see “Resize”. The best size to pick is 640X480.
4. If you want to post this picture directly on the Forum, click on IMG Code (last link), then right click on that and COPY. If you only want to post the link to the picture, click on Direct link, then right click and COPY. Then you got it in your clipboard (from where you Paste).
5. Now you can paste this into your posting. If you chose IMG, the picture will only show up AFTER you posted. In the posting you will only see the link. If you chose "Direct link", it will just be a link.

dragont225, there is something unusual going on here, just as you said. For the next step, let's have you run chkdsk on the C: drive. Open a command prompt window from Start -> All Programs -> Accessories -> Command Prompt. At the prompt, enter:
chkdsk /F c:

It should tell you that the volume is in use and ask if you would like to schedule it to be checked on the next reboot. Answer Y, for yes, then reboot the system so the chkdsk will run as Windows is booting up. (If you get any other prompts, answer N for no).

You need to watch the chkdsk run, because the results will only stay on the screen for a few seconds. A good run, with no errors, will say "Windows has checked the disk and found no problems". If there are errors to be fixed, the message will be "found problems and fixed them". Keep running chkdsk until it says it found no problems. If you do see problems that are fixed, make a note of them if you can.

1. you have this unexplainable storage situation on your disk
2. then you do not find the Snipping Tool in Accessories
3. now the CHKDSK does not work

Just for checking Command Prompt, open Cmd again (open as administrator) and type VSSADMIN LIST SHADOWSTORAGE and lets see whether it accepts the VSSADMIN command.
Another thought: A lot of people had trouble with AVG. I suggest you uninstall AVG (use the Revo uninstaller which you set to "Advanced" - the 4th option). Then install the free Avast instead.

ScootW, Thanks for pointing that out. I always fall into the same trap - thinking the whole world is Vista. I guess I better stay out of that since it is XP. Still think AVG could have thrown a monkey wrench. For scanning he might try SuperAntiSpyware.

By "cleared", I'm assuming you mean you deleted the files. What amount of files did you delete? Would they add up to the lost space? Did you make sure to empty the recycle bin? Either way, good luck to you.

I found out that everytime i download a programme, the amount of free space available decreases even after I completely remove the programme and all files I can find. Anyone has any idea why this happens and where might be the other files ( if any ) I have not deleted so I can delete them.

dragont225, file system corruption could account for missing space that doesn't return. That's why you really need to run chkdsk on all partitions. Since it doesn't run from the OS, you could run it from the Recovery Console. Here is Microsoft's KB article about Recovery Console:http://support.microsoft.com/kb/307654

Basically, you boot from your XP installation CD, or find Recovery Console on your "F8" menu (Advanced Boot Options). Go to a command line in Recovery Console and you can run "chkdsk /F x:" for every partition, x:, that you have.